Daily polysubstance use associated with HIV, HCV, and non-fatal overdose among people who inject drugs: A latent class analysis using nationwide data.

BACKGROUND

This study examined how distinct patterns of polysubstance use are associated with non-fatal overdose, human immunodeficiency virus (HIV) infection, and lifetime hepatitis C virus (HCV) infection among persons who inject drugs (PWID).

METHODS

PWID were recruited from 23 U.S. cities for the 2018 National HIV Behavioral Surveillance. Latent class analysis was conducted using eight daily substance use indicators, including cannabis, opioid injection, cocaine-crack injection, methamphetamine injection, opioid non-injection, cocaine-crack non-injection, methamphetamine non-injection, and benzodiazepine non-injection. Associations between latent classes and sociodemographic variables, behavioral risk factors and non-fatal overdose, HIV infection, and lifetime HCV were analyzed using the R3STEP and Vermunt's 3-Step procedure.

RESULTS

In total, 11,347 PWID were included in the analysis. Four classes were determined: 1) Opioid-Only Injection (46.79%), 2) Polydrug-Polyroute (4.07%), 3) Cocaine Dominant Polyroute OSPU (35.96%), and 4) Meth Dominant Polyroute OSPU (13.18%). After adjusting for covariates (e.g., sociodemographic, psychological distress, sexual and physical violence, attending drug treatment in the past 12 months), the Opioid-Only Injection class had a higher proportion of PWID who tested positive for HIV than all polysubstance classes and higher lifetime HCV than the Polydrug-Polyroute and Cocaine Dominant Polyroute OSPU classes. The polysubstance use classes had higher proportions of non-fatal overdose than the Opioid-Only Injection class, and the Polydrug-Polyroute class had greater non-fatal overdose episodes than all other classes.

DISCUSSION: This study identified four novel polysubstance-polyroute typologies and their unique relationships with non-fatal overdose, HIV, and HCV risk among a nationwide sample of PWID. Interventions to mitigate infectious disease and non-fatal overdose risk among PWID may benefit from tailoring responses based on the needs of specific drug use combinations that individuals use daily.